← All parts of this equation

Equation 5 · Part 2 · The Metabolism of Civilization: Energy to 2100

Symbol z

c(z)=c0(zz0)−bc(z) = c_0 \left( \frac{z}{z_0} \right)^{-b}
zz

What this part means

z is an argument of the function-like quantity on the left; its role is set by that function’s stated inputs.

Its job in the formula

z is an argument of the function-like quantity on the left; its role is set by that function’s stated inputs.

The passage around this formula

…entire forecasting method on a stochastic version of it, fitted to more than fifty technologies’ historical cost and production records [ 1 ] . Written in its cleanest form, cost c at cumulative production (experience) z relates to a reference cost c0c_0 at reference experience z0z_0 by: c(z)=c0(zz0)−bc(z) = c_0 \left( \frac{z}{z_0} \right)^{-b}. where the experience exponent b sets the learning rate LR = 1 - 2^{-b} , the fractional cost drop for every doubling of z . Way et al.'s working version of the same relationship is stated as a stochastic…

Read this part in the article →

Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

Open the illustrated variables: a letter stands for a value guide →

See this notation across published equations →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.